index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Accediendo a los valores de un radio button</title>
<script src="https://d3js.org/d3.v5.min.js"></script>
</head>
<body>
<div>
<label for="male">Male</label>
<input checked type="radio" name="gender" id="male" value="male"><br>
<label for="female">Female</label>
<input type="radio" name="gender" id="female" value="female"><br>
<label for="other">Other</label>
<input type="radio" name="gender" id="other" value="other"><br><br>
</div>
<script>
console.log( d3.select('input[name="gender"]:checked').property("value") );
d3.selectAll('input[type="radio"]').on("change",function(d){
console.log( this.value );
})
</script>
</body>
</html>